päävirta

Päävirta is a Finnish noun meaning "the main current" or "the primary flow." It is used in technical, geographical, and metaphorical senses. Etymology: from pää ("head, main") and virta ("flow, current").

In electrical engineering and power engineering, the term describes the primary current in a circuit or the main power supply line; it contrasts with auxiliary currents, and safety devices often control or monitor the päävirta to ensure proper operation. In hydrology and geomorphology, päävirta denotes the main channel of a river—the trunk stream that carries the majority of the discharge, as distinguished from tributaries.

In cultural and social discourse, päävirta is used figuratively to describe the mainstream or prevailing trend, opinion, or media landscape, similar to valtavirta. The word is common in Finnish technical literature and in everyday language when pointing to the dominant or central flow in a system. Because it is a general term rather than a fixed proper noun, there is no single authoritative definition; context determines whether it refers to electrical circuits, river systems, or cultural discourse.